Simple, material-efficient microgranulation methods are disclosed for aggregating precursor particles into larger product particles with improved properties and, in some instances, novel structures. The product particles are useful in applications requiring uniform, smooth, spherical, or rounded particles such as for electrode materials in lithium batteries and other applications.

Simple, material-efficient microgranulation methods are disclosed for aggregating precursor particles into larger product particles with improved properties and, in some instances, novel structures. The product particles are useful in applications requiring uniform, smooth, spherical, or rounded particles such as for electrode materials in lithium batteries and other applications.

A hydrothermal synthesis for LiFePO.sub.4 is provided. First, each raw material solution is prepared using a degassed water in advance, second, those solution are mixed by dripping in a fixed order, and then those materials are reacted in a hydrothermal synthesis, so that LiFePO.sub.4 is obtained in a predesigned form.

A hydrothermal synthesis for LiFePO.sub.4 is provided. First, each raw material solution is prepared using a degassed water in advance, second, those solution are mixed by dripping in a fixed order, and then those materials are reacted in a hydrothermal synthesis, so that LiFePO.sub.4 is obtained in a predesigned form.

A method of making a disordered rock salt cathode material for lithium-ion batteries includes performing combustion synthesis with an aqueous solution of metal-containing compounds. The method may include a two-stage process having a first stage followed by a second stage. The first stage includes performing combustion synthesis to obtain a metal oxide precursor. The second stage includes one or more of lithiating, fluorinating, and annealing the metal oxide precursor to obtain a disordered rock salt (DRX) oxide or oxyfluoride. The obtained disordered rock salt (DRX) may have a chemical composition Li.sub.1+xMn.sub.yTM.sub.1-x-yO.sub.2-zF.sub.z wherein 0x0.3, 0.4y1, 0z0.3, and TM is one or more transition metals selected from a group of Ti, Zr, Mo, Nb, and V. A lithium-ion battery cathode including a disordered rock salt cathode material and a lithium-ion battery including the lithium-ion battery cathode are also provided.

A method of making a disordered rock salt cathode material for lithium-ion batteries includes performing combustion synthesis with an aqueous solution of metal-containing compounds. The method may include a two-stage process having a first stage followed by a second stage. The first stage includes performing combustion synthesis to obtain a metal oxide precursor. The second stage includes one or more of lithiating, fluorinating, and annealing the metal oxide precursor to obtain a disordered rock salt (DRX) oxide or oxyfluoride. The obtained disordered rock salt (DRX) may have a chemical composition Li.sub.1+xMn.sub.yTM.sub.1-x-yO.sub.2-zF.sub.z wherein 0x0.3, 0.4y1, 0z0.3, and TM is one or more transition metals selected from a group of Ti, Zr, Mo, Nb, and V. A lithium-ion battery cathode including a disordered rock salt cathode material and a lithium-ion battery including the lithium-ion battery cathode are also provided.

A positive electrode active material includes a core and a shell enveloping the core. The core contains Li.sub.1+xMn.sub.1yA.sub.yP.sub.1zR.sub.zO.sub.4, where A is one or more selected from Zn, Al, Na, K, Mg, Mo, W, Ti, V, Zr, Fe, Ni, Co, Ga, Sn, Sb, Nb, and Ge, and R is one or more selected from B, Si, N, and S. The shell includes a first coating layer and a second coating layer. The first coating layer includes a pyrophosphate MP.sub.2O.sub.7 and a phosphate XPO.sub.4, where M and X each are one or more independently selected from Li, Fe, Ni, Mg, Co, Cu, Zn, Ti, Ag, Zr, Nb, and Al. The second coating layer is a doped carbon layer, where a doping element in the doped carbon layer includes any one or more selected from nitrogen, phosphorus, sulfur, boron, and fluorine.

A positive electrode active material includes a core and a shell enveloping the core. The core contains Li.sub.1+xMn.sub.1yA.sub.yP.sub.1zR.sub.zO.sub.4, where A is one or more selected from Zn, Al, Na, K, Mg, Mo, W, Ti, V, Zr, Fe, Ni, Co, Ga, Sn, Sb, Nb, and Ge, and R is one or more selected from B, Si, N, and S. The shell includes a first coating layer and a second coating layer. The first coating layer includes a pyrophosphate MP.sub.2O.sub.7 and a phosphate XPO.sub.4, where M and X each are one or more independently selected from Li, Fe, Ni, Mg, Co, Cu, Zn, Ti, Ag, Zr, Nb, and Al. The second coating layer is a doped carbon layer, where a doping element in the doped carbon layer includes any one or more selected from nitrogen, phosphorus, sulfur, boron, and fluorine.